1/3 cup butter
1/3 cup flour
¾ teas. Salt
1 ½ cups milk
6 eggs, separated
¾ teas. Cream of tartar
Melt butter in medium saucepan.  Blend in flour and salt.  Cook, stirring constantly until smooth and bubbly.  Sir in milk all at once.  Cook and stir until mixture boils and is smooth and thickened.   Set aside.
In large mixing bowl, beat egg whites with cream of tartar at high speed until stiff but not dry, just until whites no longer slip when bowl is tilted.  Thoroughly blend egg yolks, additional ingredients and seasoning, if desired, into rserved sauce.  Gently , but thoroughly fold yolk mixture into whites.  Carefully ppour into 1 ½ to 2 quart souffle dish or casserold.
If desired, create “top hat” effect by using a narrow spatula or spoon to cut through mixture in a ring about 1 inch from sides and 1 inch deep (this will cause center to rise higher than sides)  Bake in 350 degree oven about 30 to 40 minutes, until puffy, delicately browned, and a knife inserted in center comes out clean.  Serve immediately.  Makes 4 to 6 servings.
VARIATIONS
CHEESE:  Add to thickened sauce 1 to 1 ½ cups shredded  cheddar swiss or mozzarella cheese and ½ tsp. Dry mustard.
FLORENTINE PLUS: Add 1 package frozen chopped spinach or broccoli, cooked and well-drained, ¼ to ½ cup shredded swiss or cheddar cheese and 1 teas. Instant chicken bouillon.
SEAFOOD:  Add 6 ½ to 7 oz. Can shrimp, well-drained, or crabmeat, salmon or tuna, drained and flaked, ½ cup shredded swiss cheese, ½ teaspoon instant minced onion and ½ teas. Dried dill weed.
POULTRY;  Add 1 cup finely chopped, cooked chicken or turkey, ½ cup shredded  Swiss cheese, ½ tsp. Celery seed and ½ tsp. poultry seasoning.
VEGETABLE:      Add 1 cup finely chopped or shredded cooked, well drained vegetable, ½ cup shredded cheddar, swiss or mozzrella cheese and ½ tsp. Basil, thyme, marjoram or oregano leaves, crushed.